Steel tape rule



F. o. CARLSON STEEL TAPE RULE Oct. 4, 1938.

Filed Aug. 19, 1937 a M a. m a A. M

z 5 a Z m a m INVENTOR, Frederic: K O. Carlson 81;, 8 y E /J ATTORNEY.

Patented Oct. 4, 1938 UNITED STATES PATENT OFFICE STEEL TAPE RULE Application August 19, 1931, Serial No. 159,891

3 Claims.

This invention relates to improvements in measuring devices of the type employing a spring steel tape of transversely curved cross-section. and more particularly relates to improved form of braking device in combination therewith.

An important object of this invention is to provide a brake for a steel tape of this type, the operation of which is dependent upon the inherent resiliency of the tape.

A further object of the invention is to provide an inherently resilient brake shoe or saddle which functionally cooperates with the inherently resilient steel tape.

A still further object of the invention is to provide a brake structure which automatically compensates for the manufacturing tolerances encountered in such devices.

A general object of the invention is to provide an improved form of braking mechanism which is exceedingly simple in structure, and inexpensive to manufacture, while being highly effective for its intended purposes and adequately rugged to withstand ordinary usage to which it will be subjected.

Other objects will be apparent from the fol lowing detailed disclosure.

This invention resides substantially in the com bination, construction, arrangement and relative location of parts all in accordance with the scope of this disclosure.

In the accompanying drawing,

Figure 1 is a front elevational view of a steel tape measuring device in accordance with this invention;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a plan view of one of the casing sections looking into the interior thereof;

Fig. 4 is a plan view of the actuating device for the brake;

Fig. 5 is a front elevational view of the brake shoe or saddle showing its operative relationship to the steel tape;

Fig. 6 is a top plan view of the brake shoe or saddle.

5 The complete nature and scope of the invention can best be understood by first setting forth the full and detailed description of the construction. In the form of steel tape measuring devices illustrated, there is employed a casing composed 50 of two mating sections, 4 and 2; the casing section I is provided with a projection 3 on its inner face which has a recess 4 to receive the end of the axle or shaft 6. The axle or shaft 6 is secured in any suitable manner to the inner wall of the eas- 66 ing section 2 so that its free end will fit into the recess 4 when the casing section mates. The hole 5 is provided in the casing section I through which a screw engages the shaft to hold the entire device in assembled position. To facilitate the proper relative positioning of the casing section, the section I is provided with pins 9 and H! which fit in properly positioned recesses in the other casing section. The steel tape and the spring normally used in conjunction therewith, are formed into a coil as indicated diagrammatically at 8, and the inner end is attached to the shaft 6. The free end I I of the tape projects through an opening formed by the casing sections. This opening is defined by a thickened portion l3 of the casing section, which, when together, form a table or 15 anvil over which the tape slides and by the thickened portions i6 vertically spaced thereabout. These features of construction are old and well known in the art, and by themselves form no part or this invention. a

The two halves l3 of the anvil have their top faces inclined downwardly from the side walls of the casing section to their outer faces, and inclined upwardly from their front faces towards the rear as indicated by the reference numeral It. The lower face of the casing at the anvil is cut away in accordance with usual practice as indicated at l5 to provide the usual thumb nail space by means of which the hook 28, secured to the free end it of the steel tape, may be engaged 30 when the tape is fully withdrawn into the case.

Spaced above the rear ends of the anvil sections are the pins l2, one of which is integrally mounted upon the inner wall of each casing section so as to be aligned when the casing sections 35 are assembled. This provides a guide for the end of the tape to hold it on the anvil. Formed in the side wall of each section casing, so as to be aligned, are the openings l l which lie between the guides l6 and the guide pins l2. As clearly shown 40 in Figures 1 and 5, the steel tape itself which of course is suitably graduated, is of the concave convex type made of spring steel.

When the casing sections are assembled there is slidably mounted in the openings H, a brake actuating button member which is generally cylindrical in form. It is made up of end portions l8 and It at the inner ends of which are the enlarged portions 20 and 2| to form stop collars. Extending inwardly from the enlarged portion 20 is a conical portion 22 which terminates in the cylindrical portion 23 of reduced diameter. This cylindrical portion in turn extends into a sharply inclined conical portion 24 and then into a cylindrical portion 25 of greater diameter than the portion 23, but of less diameter than the portions 2! and It. When the taping sections are assembled the button or actuating member is siidable transversely in the openings II a limited distance as determined by the flanges 20 and ii.

Interposed between the actuating member and the steel tape is the saddle or brake shoe 2! which is made of spring steel but is somewhat more resistant to distortion than is the steel tape II. The saddle consists of inclined side portions terminating in a slightly rounded apex portion 26a at their upper end, and in the horizontal terminal flanges 21. The apex portion its forms a sort of cam follower which cooperates with the actuating button.

When the brake is released the actuating member is in the position shown in Figure l, at which time the cam follower portion 28a of the saddle is under the reduced cylindrical portion 23. It may be noted that the saddle lies between the projection l6 and the pins i2, and is held in position for that reason as well as by the actuating member and the tape. In the position of the.

actuating member just described, the saddle is relatively free so that the tape may be freely moved in and out of the casing. When it is desired to apply the brake the projecting end I9 of the button is pushed in until the flange 20 stops it. When the sharply inclined collar portion 23 engages the cam follower 26a, it forces the saddle downwardly tending to flatten out the curved tape II which is pressed against the inclined wall sections ll of the anvil. When the actuating member comes to rest, the cylindrical portion 25 thereof engages the cam follower 26a. It will be seen that by distorting the curved tape II, it is firmly gripped between the saddle and the anvil and resiliently held against ordinary pressures, and is sumciently freely held so that under sufficient force the tape may be moved. Hence when the tape is locked in any desired position adequately for all normal purposes it will be seen that the brake functions bi reason of the inherent resiliency of the tape, and of the manner in which the saddle engages it and the form of the anvil. The saddle is preferably inherently resilient but somewhat more resistant to distortion than is the tape, and by reason of the resiliency of the two, all manufacturing tolerances are compensated for. Thus, it will be seen that the spring tape itself becomes an intimate part of the brake mechanism.

It is apparent that the structure is exceedingly simple and adds but two parts, namely, the actuating member and the saddle to the ordinary concave convex spring steel tape. If desired, the flanges 21 of the saddle may havea slight downward inclination so as to tend to reduce their area of contact with the graduated face of the tape (the upper face being normally graduated) so as to minimize the tendency to mutilate the graduations. Also, if desired, the terminal edges of the flanges may be slightly downturned to engage the sides of the tape and act as a guide therefor for movement in the direction of the length of the tape.

By making the cam portion 23 of the actuated .member sharply inclined, it is possible to get a substantial movement of the saddle in a direction vertical to the tape with a relatively short movement of the actuating member. The result is that in releasing the saddle when the cam follower ila reaches this inclined portion, the resiliency of the tape and the saddle tend to kick the actuator to thoroughly released position. These functions facilitate the ease with which the device may be actuated.

Another advantage of the particular form of saddle construction employed is, as will be clear from Figs. 2 and 5, that the end of the hook member 28 which overlies the tape and is of less width than the tape, in accordance with common practice, may pass thereunder when the tape is fully withdrawn into the casing and the hook 28 is in the position shown in Fig. 2.

From the above description it will be apparent to those skilled in the art that the features of this invention, particularly with respect to the structural details thereof, may be readily varied by those skilled in the art without departure from the novel scope of the invention. I do not, therefore, desire to be strictly limited to the disclosure as given for purposes of illustration, but rather to the scope of the appended claims.

What I seek to secure by United States Letters Patent is:

1. In a measuring device as described the combination comprising a casing having an opening, a spring steel tape mounted in said casing and having its terminal end movable through said opening, an anvil over which the tape moves, a brake saddle positioned above the tape and an actuating member slidably mounted in the walls 4 of the casing and transversely movable thereof,

said member when slid transversely causing movements of the saddle towards and away from the anvil whereby the tape is gripped between it and the anvil.

2. In a measuring device the combination comprising a casing having an opening, a transversely curved steel tape coiled in said casing and movable through said opening, an anvil positioned adjacent to and below said opening, and a brake shoe resting on top of the tape and an actuating member for causing movement of the brake shoe towards the anvil, the braking action of the shoe resulting from its cooperation with the transversely curved spring steel tape by reason of its change from curved cross-sectional shape towards a flat cross-sectional shape, said tape aiding in the return of the actuating member to unlocking position.

3. In a measuring device as described the combination including a casing having an opening therein, an anvil forming part of the casing and mounted at but below said opening, a transversely curved spring steel measuring tape coiled in said casing and movable through said opening over the top of said anvil, a saddle resting on said tape so as to engage it near its side edges, and a transversely movable cam member slidably mounted in the casing in engagement with the saddle, sliding movements of the cam member thereof effecting vertical movements of the saddle with respect to the tape.

FREDERICK O. CARLSON. 

